Loom Spider

Spider silk is known on many worlds to be a strong, lightweight material, but most worlds don't get around to doing much with it until well into their technological development. Plavithen is fortunate to have a work-around for this problem: the loom spider.
Loom spiders look like gigantic jumping spiders - a typical specimen is about the size of a human hand. They have a slightly "cartoonish" look to them and the fuzz that covers them is softer than normal for an arachnid. They eat a diet of mostly giant beetles and berries, have a disposition similar to that of an affectionate rabbit, and tend to live for about 15 years. They also have extremely productive and efficient spinnerets, and can be trained not to produce adhesive along with the silk they weave. All of this makes them ideal for production of spider silk goods, which the elves of Plavithen use them for extensively.
Unsurprisingly, the loom spider is not a naturally-occurring species on Plavithen. They, like a number of species currently living on the planet, owe their existence to first-world bio-engineering.
Most elven households keep at least one loom spider around as a pet and source of small amounts of useful spider silk, and they enjoy a role in elven society similar to that of a housecat. However, as the world has become more advanced, larger spider farms have become more common, with hundreds or even thousands of spiders. The spiders produce poorly (or not at all) if not treated well, so for those without arachnophobia, they can be an enjoyable place to visit, as visitors quickly acquire a retinue of curious, but friendly spiders.
Spider silk is used in clothing and armor, but the elves also make ropes, containers, and even sails out of it. Some of the most sought-after sailcloth is entirely or partially made of spider silk, and it is highly-resistant to wear and tearing.